This invention relates to an imaging system for a missile which rotates about a principal axis, comprising an imaging lens arrangement and a detector arrangement situated in the focal plane of the imaging lens arrangement for the generating of electric image signals which are processed while the respective rotating position of the missile is taken into account.
Infrared imaging systems for missiles are known which comprise an imaging lens arrangement which is fixed to the missile and an electro-optic detector mosaic which is also fixedly connected with the missile and which is composed of detector elements which are distributed flatly in the focal plane of the imaging lens arrangement and are scanned line-by-line. For a satisfactory image definition, imaging systems of this type require a very large number of detector elements and are therefore correspondingly expensive.
Infrared imaging devices are also known (German Patent Documents DE 30 07 893 A1; DE 30 48 496 C1) in which field of view of the imaging lens arrangement swivels mechanically by means of an oscillating deflecting mirror or a gyroscopic drive, for example, over the viewed scene that is of interest and as a result, a linear or circular image scanning is achieved by means of a single row of detectors which extends over the field of view of the imaging lens arrangement. The mechanical complexity for an exact control of the image movement and the computing volume needed for the correlating of the individual image signals to the corresponding image points are considerable.
It is an object of the invention to develop the imaging system of the initially mentioned type in such a manner that a perfect image quality with a high image resolution can be achieved in a manner that is simple with respect to the construction and signal technology and has comparatively few detector elements.
According to the invention, this object is achieved by means of an imaging system of the above-mentioned type, wherein the detector arrangement 8 and the imaging lens arrangement 6 with their optical axis are arranged carrying out the same motion as the missile 2 to be rotating about a principal axis (A) of the missile, and the detector arrangement comprises one or several detector row 14 extending toward the axis of the missile.
According to preferred embodiments of the invention, a complicated mechanical image control is not needed. By means of a targeted utilization of the self-rotation of the missile in conjunction with the detector arrangement, which is radial with respect to the missile axis and comprises relatively few individual elements, a continuous image rotation is achieved in a constructively very simple manner and with an image scanning which is polar with respect to the missile axis. Thus, from the image signals according to the respective rotating position of the missile as well as the radial distance of the individual detector elements from the axis of rotation of the missile, a non-rotating image of the viewing scene that is of interest is obtained with low computing expenditures and a high image resolution. Because of its simple construction and its high image quality, the imaging device according to the invention is excellently suited for rotating missiles, but naturally also for other moved carrier systems which carry out a continuous rotation about a principal axis.
In further advantageous aspects of preferred embodiments of the invention, instead of a single detector row, preferably several detector rows are provided which are each arranged to be angularly offset to one another with respect to the missile axis, whereby, in a very simple manner, specifically by the corresponding selection of the frequency sensitivity of the individual detector rows, a frequency-selective image scanning and/or an image scanning frequency increase can be achieved with respect to the rotational frequency of the missile.
In order to be able to change the field of view of the imaging lens arrangement, this imaging lens arrangement is preferably adjustable in a swivelling manner with respect to the missile axis, while the detector rows, for reasons of constructional simplification, are expediently rigidly connected with the missile. In the case of a swivelling fastening of the imaging lens arrangement, the detector rows are in each case constructed preferably configured to have a circular-arc shape with the center of the curvature being in the swivel center of the imaging lens arrangement.
In certain preferred embodiments a detector arrangement according to the invention for the infrared image scanning is provided, which consists of one or at most a few detector rows fixed to the missile, it was found, as another advantage of the invention, that high-expenditure cooling measures, as they are otherwise required for infrared image devices with large-area or rotating detector arrangements, are not necessary.
In order to be able to image with a high image definition the overall scene as well as scene cutouts that are of interest, it is finally recommended according to preferred embodiments to use an imaging lens arrangement with a continuously variable focal length.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.